Self propelled agricultural application machine

ABSTRACT

A self-propelled agricultural application machine comprising a chassis which carries a storage tank for the material to be applied is provided. The chassis comprises a central longitudinal beam from which at least a pair of wheels is suspended. The narrow chassis allows steerable wheels to be positioned at tolerable track widths whilst permitting a large steering angle and thus small turning radii.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §120 as a continuationof U.S. patent application Ser. No. 13/059,175 filed Feb. 15, 2011, nowU.S. Pat. No. 9,XXX,XXX, the full disclosure of which, in its entirety,is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Field of Invention

The invention relates to self-propelled agricultural applicationmachines, such as crop sprayers, which comprise a chassis which carriesa storage tank for the material to be applied.

Description of Related Art

Agricultural application machines such as crop sprayers comprise a largevolume tank carried on a chassis. Such machines can be trailed behind atractor or provided as a self-propelled unit having an integral cab andengine. The machine further comprises an extending boom which provides atransverse line of uniformly spaced spray nozzles connected by pipes tothe tank. During operation the application machine is moved acrossfields of crops such as cereals and maize to apply liquid fertilizer orchemical treatment such as herbicides, fungicides and pesticides to thecrop in a controlled manner.

The application machines are typically driven across the fieldsutilizing “tram-lines” which are often used several times throughout thegrowing cycle to make different applications, thereby minimizing thearea of lost crop through flattening by the wheels. The minimum turningradius affects the length of the tram-lines especially at the turningpoints on the headlands. In turn, this affects the area of crop which islost to providing the tram-lines.

In addition, the minimum turning radius dictates the limits of themachine to reach corners and edges of fields having complex shapes.Also, the turning radius limits the maneuverability of the machine.

BRIEF SUMMARY OF THE INVENTION

It is thus an object of the invention to provide a self-propelledagricultural application machine with a reduced minimum turning radius.

It is another object of the invention to provide a self-propelledagricultural application machine which has a reduced assembly time.

According to the invention there is provided a self-propelledagricultural application machine comprising a chassis which carries astorage tank for the material to be applied, the chassis comprising asingle central longitudinal beam from which at least a pair of wheelsare suspended. By forming the chassis from a single beam in this way,the steering angle of steerable wheels can be increased whilst stillkeeping the track width within constraints set by maximum widthspermitted on highways.

In some countries, such as The United Kingdom, rural highways aretypically narrow and limit the width of self-propelled applicationmachines. The resulting separation between the steerable wheels and aconventional chassis is often inadequate to permit a satisfactorysteering angle. To compound the problem of large turning radii,application machines often employ wheels of large diameter to achievesufficient ground clearance. By providing a central longitudinal beam toprovide a ‘backbone’ for the machine in accordance with the invention,the separation between the wheels and the chassis can be increased, inturn increasing the maximum steering angle without sacrificing wheeldiameter.

In a preferred arrangement the application machine comprises two pairsof wheels which are suspended from the longitudinal beam. At least oneof the two pairs of wheels are steerable. Preferably, both pairs ofwheels are steerable delivering even smaller turning radii. As mentionedabove, the provision of a central longitudinal beam allows increasedturning angles. In one preferred embodiment, the steerable wheels have amaximum steering angle which is greater than 35 degrees, for example 37degrees.

The wheels are preferably independently suspended from the longitudinalbeam.

Preferably, the application machine further comprises a cab which issupported forwardly of the longitudinal beam by a cab support structurewhich is itself supported by the longitudinal beam. Advantageously, thisplaces the cab in front of the chassis rather than on top. In turn thisimproves the forward visibility for the driver. Furthermore, the cab isdisposed lower which lowers the vehicle's centre of mass thus increasingthe stability thereof.

Preferably, the application machine further comprises a boom assemblywhich is suspended from the rear section of the longitudinal beam.Advantageously, this permits a single, centrally-disposed, parallelogramsuspension structure to be employed instead of the conventional doublestructure. This reduces the number of components required thus savingcost.

The boom assembly is preferably pivotally mounted to the longitudinalbeam to allow the boom assembly to be raised and lowered. A boom liftactuator may be provided and connected between the longitudinal beam andthe boom assembly to lift and lower the boom assembly.

In a preferred embodiment the application machine further comprises anengine which is disposed to one side of the longitudinal beam andbetween two wheels on one side of the machine. The central longitudinalbeam structure permits the engine to be located on a similar level tothe chassis rather than above as in conventional self-propelledapplication machines. This lowers the centre of mass and improves thestability of the vehicle. Furthermore, access to the engine formaintenance is improved because there is no need for the operator toclimb on top of the vehicle frame. This is both safer and moreconvenient.

Preferably, the engine comprises an output drive shaft which istransversely orientated. Conveniently, this permits the pumps and/ortransmission components connected to the output of the engine to belocated on the other side of the longitudinal beam opposite the enginethus distributing the weight more evenly.

The application machine may further comprise a fuel tank which isdisposed to one side and forwardly of the longitudinal beam. Todistribute the overall weight more effectively, the fuel tank ispreferably disposed on the opposite side of the longitudinal beam tothat of the engine.

In one preferred arrangement the fuel tank is disposed under the cabwhich optimises the available space and maintains a low centre of mass.

The storage tank may be asymmetric about a longitudinal vertical planealong the centre of the chassis. By moving away from the conventionalsymmetrical tank profile, cavities and spaces within the overall machineprofile which are present only on one side thereof can be exploited tostore application material so as to optimise the available volume whilstincreasing the design flexibility to centralise the centre of mass. Anasymmetric tank lends itself well to a machine with a relatively heavycomponent, for example the engine, having a centre of mass which isoffset from the plane of asymmetry. In this case, the volume of thestorage tank disposed to one side of the plane is preferably greaterthan the volume of the storage tank disposed to the other side.Advantageously, this allows the mass of a laden tank to counterbalancethe weight of the heavy component thus increasing the stability of themachine.

In a preferred embodiment, an engine which is disposed on one side ofthe chassis and a portion of the storage tank is disposed on the otherside of the chassis so as to counterbalance the weight of the engine. Ina preferred arrangement, said portion is disposed opposite the engine soas to reduce any torsional force in the chassis.

Furthermore, by providing said portion of the tank by extending thevolume of the tank downwardly into an available cavity, the advantageouscounterbalancing effect remains even when the application material loadis low. In other words, the last part of the tank to empty is thecounterbalancing portion thus improving stability until the end of theapplication session.

This summary is provided to introduce concepts in simplified form thatare further described below in the Description of Preferred Embodiments.This summary is not intended to identify key features or essentialfeatures of the disclosed or claimed subject matter and is not intendedto describe each disclosed embodiment or every implementation of thedisclosed or claimed subject matter. Specifically, features disclosedherein with respect to one embodiment may be equally applicable toanother. Further, this summary is not intended to be used as an aid indetermining the scope of the claimed subject matter. Many other noveladvantages, features, and relationships will become apparent as thisdescription proceeds. The figures and the description that follow moreparticularly exemplify illustrative embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention will become apparent from thefollowing description of specific embodiments with reference to theappended drawings in which—

FIG. 1 is a perspective view of a self-propelled agricultural sprayer inaccordance with the invention;

FIG. 2 is a side view of the sprayer of FIG. 1;

FIG. 3 is a perspective view of the chassis of the sprayer of FIG. 1;

FIG. 4 is an underside view of the sprayer of FIG. 1 (with engineremoved);

FIG. 5 is another underside view of the sprayer of FIG. 1;

FIG. 6 is a plan view of the part of the sprayer shown in FIG. 3;

FIG. 7 is a perspective view of the tank of the sprayer of FIG. 1;

FIG. 8 is a plan view of the tank of FIG. 7; and,

FIG. 9 is a rear view of the tank of FIG. 7.

Corresponding reference characters indicate corresponding partsthroughout the views of the drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIGS. 1 to 6, a self-propelled arable crop sprayer 10comprises a pair of front wheels 12 and pair of rear wheels 14 eachwheel being separately mounted to a chassis 100 by respective variableheight suspension means. The sprayer 10 further comprises a tank 15, aboom assembly 16 and driver's cab 17. The tank 15 accounts for themajority of the sprayer's volume and serves to hold the liquid materialwhich is to be applied to a field. By way of example, the liquidmaterial may comprise fertilizer or other chemical treatment such asherbicides, fungicides, pesticides or growth restrictors.

The liquid material is delivered in a controlled manner to spray nozzles(not shown) located on the boom assembly 16 by a network of supply pipes(not shown). In the transport mode (shown in FIGS. 1 and 2) the boomassembly 16 is retracted so as to remain substantially within theprofile of the vehicle body thus allowing safe movement on the highway.In an operating mode the boom assembly 16 is extended so as to provide atransversely extending boom, having a width of 24 meters for example.Driven across an arable field, the liquid material is sprayed onto thecrop in strips 24 meters wide at a time. The driver located in cab 17controls the steering of the sprayer and the control of the liquidmaterial application. It should be understood that FIGS. 1 and 2 showonly one half (right-hand side) of the folded boom assembly 16.

With reference to FIGS. 3 to 6, the chassis 100 comprises a single,centrally-disposed, longitudinal beam 110 to which the respective wheeland boom suspension means are mounted. A first section 110 a of thelongitudinal beam 110 extends from the rear of the sprayer 10 toapproximately a region between the front wheels 12. A second section 110b is connected to the first section 110 a and extends forwardly at alower height to the front of the sprayer 10.

All four wheels 12, 14 are steerable. Each of the four wheels 12, 14 issuspended from the longitudinal beam 110 by a respective wheelsuspension assembly 115 which may, or may not, allow for adjustments tothe suspension height of the chassis 100 and/or adjustments to the trackwidth, that is the distance between opposite wheels. Each wheelsuspension assembly is secured to the longitudinal beam 110 byappropriate means, for example by brackets bolted to the undersidethereof.

By forming the chassis 100 from a single beam 110 in this way, thesteering angle of the steerable wheels 12, 14 can be increased whilststill keeping the track width within constraints set by maximum widthspermitted on highways. As can be seen from FIG. 4, the maximumachievable steering angle .theta. can exceed 30 degrees thus making thechassis arrangement particularly attractive to farmers and contractorsdesiring small turning radii from their application machines.

A further advantage of the chassis architecture is that it allows theengine 111 to be mounted to one side of the chassis 100 (see FIG. 5)thus lowering the overall centre of mass. Further, the lower positioningof the engine 111 improves access for the operator thus makingmaintenance far easier and safer. The engine 111 is conveniently locatedin the space provided between the two wheels 12, 14 on the right-handside of the sprayer 10. An output drive shaft 112 which is driven by theengine 111 is transversely orientated with respect to the direction oftravel of the sprayer 10. The drive shaft 112 is connected through thelongitudinal beam 110 to hydraulic pumps 113 associated with the sprayerpropulsion and spraying gear located on the left-hand side of thesprayer 10.

The second section 110 b of the longitudinal beam 110 provides part of acab support structure referenced generally at 117 in FIG. 3. Thelongitudinal part 110 b has connected thereto a plurality of transversecomponents 118 to adequately support the weight of cab 17. By providingthe cab support structure 117 at a lower height to that of the firstsection 110 a of the longitudinal beam, and thus the tank 15 supportedthereon, the centre of mass and the overall height of the sprayer islowered. Furthermore, the driver's visibility of the crop is improved.

A lower platform 120 is attached to the second section 110 b so as to bepositioned to the left-hand side of the cab 17. A raised platform 122 isattached to the first section 110 a by a platform support structure 123so as to be positioned behind the cab 17. A set of steps 124 is providedbetween the lower platform 120 and the raised platform 122 to allow adriver to reach the latter. From the raised platform 122, a driver isable to access the top of the tank 15.

Turning to the rear of the chassis 100, a boom support structure 130 issecured to the rear of the longitudinal beam 110. The boom assembly 16is pivotally mounted to the boom support structure 130 to allow the boomassembly 16 to be raised and lowered. A boom lift actuator (not shown)is connected between the boom support structure 130 and the boomassembly 16 to lift and lower the boom assembly.

With reference to FIGS. 7, 8 and 9, the storage tank 15 is formed ofmoulded plastic and has a volume of 4500 litres for example. As can beseen from FIG. 9, the tank 15 comprises a downwardly-extending portion150 on the left-hand side which is not reflected about longitudinal andvertical plane X. In other words there is not an equivalent volumeextension on the right-hand side. Therefore, in accordance with theinvention, the tank is asymmetric about the longitudinal vertical planeX at least across the horizontal section Y (FIG. 6).

Furthermore, as can be seen from FIG. 8, the tank comprises aforwardly-extending portion 155 on the left-hand side which is also notreflected about plane X. This forward portion 55 comprises a cappedfiller hole 156 for filling the tank 15 with application material,typically via a hose (not shown).

The two volume extensions 154, 155 deliver a significantly greater tankvolume on the left-hand side than on the right-hand side. The weight ofthe engine 111 is thus counterbalanced by the asymmetry therebyimproving the overall stability of the sprayer 10.

The downwardly-extending portion 154 is disposed opposite the engine 111thus minimizing any torsion forces on the relatively narrow chassis 100.Moreover, being the lowest part of the tank 15, the portion 154 is thelast part of the tank to empty during an application to a field.Therefore, even when the level of application material present in thetank 15 is low, the weight of the side-disposed engine 111 iscounterbalanced.

The sprayer 10 further comprises a fuel tank also disposed on theright-hand side of the chassis 100. The downwardly-extending portion 154serves also to counterbalance the weight of the fuel tank and the fuelcontained therein across the longitudinal plane X.

The tank 15 also comprises an extraction pipe 58 located at the bottomof the downward extension 54 to extract the application material duringoperation.

In summary, there is provided a self-propelled agricultural applicationmachine comprising a chassis which carries a storage tank for thematerial to be applied is provided. The chassis comprises a centrallongitudinal beam from which at least a pair of wheels is suspended. Thenarrow chassis allows steerable wheels to be positioned at tolerabletrack widths whilst permitting a large steering angle and thus smallturning radii.

From reading the present disclosure, other modification will be apparentto persons skilled in the art. Such modifications may involve otherfeatures which are already known in the field of agriculturalapplication machines and component parts therefore and which may be usedinstead of or in addition to features already described herein.

1. A self-propelled agricultural application machine comprising: achassis comprising a central longitudinal beam from which are suspendedat least one front wheel and at least one rear wheel; a storage tank formaterial to be applied mounted on the chassis, wherein the storage tankpositioned on the chassis so that it extends on both sides of thecentral longitudinal beam but is asymmetric about a longitudinalvertical plane along the centre of the chassis such that the volume ofthe storage tank disposed to one side of the plane is greater than thevolume of the storage tank disposed to the other side; and an enginewhich is disposed transversely offset to one side of the longitudinalbeam and longitudinally positioned between said at least one front wheeland rear wheel, wherein the volume of the storage tank is disposed tocounterbalance the weight of the engine.
 2. The application machineaccording to claim 1, wherein the engine comprises an output drive shaftwhich is transversely orientated and connected to hydraulic pumps whichare positioned on an opposite side of the longitudinal beam between thefront wheel and the rear wheel.
 3. The application machine according toclaim 1, wherein at least one of the wheels is steerable, and whereinthe steerable wheel has a maximum steering angle which is greater than35 degrees.
 4. The application machine according to claim 1, furthercomprising a cab which is supported forwardly of the longitudinal beamby a cab support structure which is itself supported by the longitudinalbeam.
 5. The application machine according to claim 1, furthercomprising a boom assembly which is suspended from the rear section ofthe longitudinal beam and, when in an operating mode, extendstransversely with respect to the longitudinal beam.
 6. A self-propelledagricultural application machine comprising: a chassis which carries astorage tank for the material to be applied, the chassis comprising acentral longitudinal beam from which are suspended a pair of frontwheels and a pair of rear wheels; a boom assembly which is suspendedfrom the rear section of the longitudinal beam and, when in an operatingmode, extends transversely with respect to the longitudinal beam; and anengine which is disposed transversely offset to one side of thelongitudinal beam and longitudinally positioned between one of saidfront wheels and one of said rear wheels on one side of the machine,wherein the engine comprises an output drive shaft which is transverselyorientated and connected through the longitudinal beam to hydraulicpumps which are positioned between the other one of said front wheelsand the other one of said rear wheels.
 7. The application machineaccording to claim 6, wherein at least one of the wheels is steerable,and wherein the steerable wheel has a maximum steering angle which isgreater than 35 degrees.
 8. The application machine according to claim6, further comprising a cab which is supported forwardly of thelongitudinal beam by a cab support structure which is itself supportedby the longitudinal beam.
 9. The application machine according to claim6, further comprising a boom assembly which is suspended from the rearsection of the longitudinal beam and, when in an operating mode, extendstransversely with respect to the longitudinal beam.